River Plate president Daniel Passarella has confirmed Erik Lamela is set to join Roma.
Lamela, 19, is considered one of the finest young talents in South America and had been expected to leave River following their relegation.
Following a meeting on Saturday between Passarella, Lamela's father, Roma director of sport Walter Sabatini and River Plate lawyer Daniel Crespo, a move has been agreed and the player is set to sign his contract in the near future.
"It went well," Passarella said. "Lamela is practically a Roma player."
Crespo added: "It's done. We are only missing the signature on the contract."
Roma are set to pay €12 million and the attacking midfielder has agreed a five-year contract.
Lamela had earlier written a message of thanks to the River supporters on his Twitter account.
"I love you all," he wrote. "I thank you for the support you've always given, helping me grow day by day. I will never forget you."